Type:
Educational Exhibit
Keywords:
PET-CT, CT, Abdomen, Education, Cancer
Authors:
J. Abreu e Silva, M. J. Magalhães, H. Duarte, C. Fernandes, S. Ramos Alves, A. Guimarães dos Santos, M. V. P. G. Almeida; Porto/PT
DOI:
10.1594/ecr2013/C-2345
Background
Definition
Peritoneal carcinomatosis is the most common malignant process in the peritoneal cavity,
defined as seeding and implantation of neoplastic cells in the peritoneum originating from several abdominopelvic primary malignancies,
namely carcinomas of gastrointestinal tract and ovary.
The presence of peritoneal carcinomatosis alters tumor staging,
with direct implications in treatment choice and prognosis.
Therefore,
early diagnosis of peritoneal tumor seeding is fundamental,
as is the assessment of its extent and distribution.
Anatomic Spaces,
Fluid Flow and Pathways of Spread in the Peritoneal Cavity
The peritoneal cavity is subdivided by peritoneal reflections and mesenteric attachments into compartments and recesses creating an interconnecting as watershed directing the flow of ascites (Figures 1 and 2).
The pathways of spread of disease in the peritoneum include (Figure 3):
- Direct invasion,
- Lymphatic metastases,
- Intraperitoneal seeding,
- Hematogenous spread.
Intraperitoneal seeding is largely directed by the intraperitoneal circulation of peritoneal fluid.
Pooling of peritoneal fluid favors deposition,
fixation,
and growth of seeded malignant cells.
The force of gravity operates to pool peritoneal fluid in depended pelvic recesses while negative subdiaphragmatic pressure directs fluid upward along paracolic gutters (Figure 2,
4 and 5).